Annexin 2 Regulates Intestinal Epithelial Cell Spreading and Wound Closure through Rho-Related Signaling

Abstract

Epithelial cell migration is a critical event in gastrointestinal mucosal wound healing and is dependent on actin cytoskeletal reorganization. We observed increased expression of an actin regulatory protein, annexin 2, in migrating intestinal epithelial cells. Small interfering RNA (siRNA)-mediated knockdown of annexin 2 expression in Caco-2 epithelial cells resulted in significant reductions in cell spreading and wound closure associated with decreased formation of filamentous actin bundles along the base of migrating cells. Because annexin 2 has been shown to influences actin cytoskeletal remodeling through targeting signaling molecules to membrane domains, we examined the membrane association and activation status of Rho GTPases after annexin 2 knockdown. We observed Rho dissociation from membranes and decreased Rho activity following annexin 2 siRNA transfection. Inhibition of cell spreading and wound closure in annexin 2 siRNA-transfected cells was prevented by expression of constitutively active RhoA. Rho colocalized with annexin 2 in lamellipodia and along the cytoplasmic face of the plasma membrane. In addition, annexin 2 was observed to co-immunoprecipitate with endogenous Rho and constitutively active RhoA. These findings suggest that annexin 2 plays a role in targeting Rho to cellular membranes, thereby modulating Rhorelated signaling events regulating cytoskeletal reorganization during epithelial cell migration. (Am J Pathol

S100A6 binds to annexin 2 in pancreatic cancer cells and promotes pancreatic cancer cell motility

“…Whether S100A6 contributes to pancreatic cancer cell motility through interaction with annexin 2 is not yet clear. However, the observed positive correlation in this study between high S100A6 levels and the localisation of annexin 2 to the plasma membrane in pancreatic cancer cells may have significance with respect to the ability of these cells to move, as annexin 2 has been implicated in the regulation of actin dynamics, cell spreading and wound closure (Hayes et al, 2006;Babbin et al, 2007;de Graauw et al, 2008). Hayes et al showed that annexin 2 was concentrated in the dynamic actin-rich protrusions of motile cells and that siRNA-mediated depletion of annexin 2 led to loss of protrusive and retractile activity (Hayes et al, 2006).…”

“…Hayes et al showed that annexin 2 was concentrated in the dynamic actin-rich protrusions of motile cells and that siRNA-mediated depletion of annexin 2 led to loss of protrusive and retractile activity (Hayes et al, 2006). More recently, Babbin et al (2007) observed that depletion of annexin 2 from Caco-2 epithelial cells resulted in reductions in cell spreading and wound closure. Finally, the work of de Graauw et al (2008) pointed towards the phosphorylation of annexin 2 as a key event in the remodelling of the actin cytoskeleton during cell spreading.…”

Identification of Novel Interaction between Annexin A2 and Keratin 17

“…39). RNAimediated silencing of AnxA2 impairs the migration of human epithelial colorectal adenocarcinoma cells (40) and glioma cells (41) and reduces the invasiveness of breast cancer cells (18), all highlighting the potential importance of AnxA2 in cancer progression.…”

Annexin A2 Regulates β1 Integrin Internalization and Intestinal Epithelial Cell Migration

“…Closure-We have previously reported that AnxA2 is up-regulated in migrating IECs and controls cell motility and wound closure (13). To further identify the mechanisms by which AnxA2 regulates epithelial cell motility, we generated cell lines with stable down-regulation of AnxA2 using two different shRNA sequences (shAnxA2) and a control cell line with a nonsilencing shRNA target (shCtrl).…”

“…We have previously reported that the calcium-dependent phospholipid binding protein, annexin A2 (AnxA2), facilitates IEC migration (13). AnxA2 is a highly conserved protein in invertebrates and plants and is expressed in most cell types.…”